The Bigger Flu Threat - - Wild Birds or Chickens?

[Guest guest]

http://www.nytimes.com/reuters/international/international-birdflu-wildbirds.htm\

l

 

The Bigger Flu Threat - - Wild Birds or Chickens?

 

By REUTERS

Published: October 31, 2005

Filed at 7:58 a.m. ET

 

HONG KONG (Reuters) - Wild migratory birds seem to

have become the world's public enemy number one since

the deadly H5N1 bird flu virus spreading in Asia was

detected this month as far west as European Russia,

Turkey and Romania.

 

Mindful that the geographical spread appears to be

tracking migratory routes of wild birds, some people

in parts of Asia have begun avoiding bird markets and

sanctuaries, and are even giving chicken dishes a

miss.

 

Last week, students who visited Hong Kong's Mai Po

wetlands, a crucial feeding stopover for wild birds on

the north-south migratory route, were seen wearing

protective masks.

 

But experts and scientists are calling for calm,

saying the biggest risk to human health rests not in

wild birds, but poultry because they live among

people, particularly in Asia and Africa.

 

What's important now is to stem the spread in poultry,

and to stop it from becoming entrenched, or endemic,

experts say.

 

``Just the introduction per se (of the virus from wild

birds to poultry) is not a major risk but if it

becomes endemic, that is the problem,'' said Malik

Peiris, a top virologist in Hong Kong who has battled

the bird flu virus since 1997, when it made its first

known jump to humans in Hong Kong, killing six people.

 

``In terms of human health, the predominant risk is

poultry because that is where there is significant

exposure to the human population. The direct risk of

migrating birds (infecting) humans is negligible --

it's like being knocked down by a bus.''

 

THE REAL RISK

 

``Once it amplifies in poultry then you have ample

opportunity for continued interaction with human

populations. The maintenance and perpetuation of this

virus is really through poultry,'' said Peiris, a

professor at the University of Hong Kong.

 

Scientists have warned for months that the virus,

which has killed over 60 people in four Asian nations

in 2003, could trigger a pandemic and kill millions

once it mutates into a form that is easily

transmissible among people.

 

The World Health Organization says there are more than

120 documented cases of people contracting bird flu,

most of whom were infected directly from poultry. The

virus's death rate in humans is nearly 50 percent.

 

Until recently, the virus remained in Asia and wild

birds are being blamed for spreading it to the eastern

edge of Europe.

 

In Hong Kong, the Mai Po wetlands have become a focal

point of discussion with some politicians calling for

a temporary closure. The reserve is a stopover for

sandpipers and plovers escaping the harsh northern

winter. They feed and refuel here before heading south

to Australia.

 

But the sanctuary's manager Lew Young says there is no

reason to panic. About 7,000 blood and fecal samples

have been taken each winter at the park since 1997 and

not one has come in positive.

 

``It's easy to blame wild birds but not poultry.

People lose money and how would the government

compensate if the World Health Organization blames the

poultry industry?'' Young said.

 

``From all the monitoring, the likelihood of the birds

having H5N1 is very small. Assuming that there are

some (infected) birds, what are the chances of the

public and staff coming into contact with the

secretions from those few birds?'' he said.

 

``Usually, wild birds see you coming and they fly away

at once. Chances of coming into contact is very small.

From our best knowledge, we are safe. But if tomorrow

a thousand birds die and are found with the bird flu,

then we will close the reserve.''

 

What is important now is to protect poultry from wild

birds and to prevent any co-mingling, experts say.

They also call for more stringent biosecurity measures

in poultry farms, keeping poultry indoors, an end to

wet markets and the habit of keeping backyard chickens

and ducks.

 

``The source of (human) infection is still in poultry.

If we can control the infection in poultry we remove

the threat both in poultry and in humans, but that is

not easy to do,'' Peiris said.

 

Some households in Indonesia, Vietnam, China, Thailand

and Cambodia -- countries affected by the virus --

keep backyard chickens and ducks and even depend on

them for food. Rather than bury dead chickens, they

would rather eat them.